Static eliminator



Feb. 16 ,1926. 1,573,414

a. H. MAHONEY STATIC ELIMINATOR Filed NOV. 20, 1924 Patented Feb. 16, 1926.

\ UNITED STA PATENT OFFI CE.

GEORGE I-I. MAHONEY, OF CHICAGO,ILLINOIS,"ASSIGNOR TO CHICAGO ENGINEERING WORKS, INC., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

STATIC CELIMINATOR.

Application filed November 20, 1924. Serial No. 751,005.

To all whom it may concern:

Be it known that I, GEORGE H. Mnrronnr, citizen oftheUnitedStates, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Static Eliminator; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art'to which it appertains to make and use the same.

My invention relates to means for dissipating the static charges produced in printing devices under certain weather conditions, so as to prevent-these charges from interfering with the ejecting, stacking and alining of the imprinted sheets.

"In using printing devices having rotating imprinting cylinders, such as theso-called inultigraphs, it is customary to have the imprinted sheets ejected successively above the delivery table of the machine, so that they can then drop upon one another. In "dry weather, and particularly on cold days, the static electric efiects produced by friction on the sheets during their imprinting interfere with the normal collecting of the imprinted sheets in this manner. This occurs partly because the similar charges produced on the successive sheets cause these sheets to repel each other, thereby tending to keep them apart and preventing them from dropping flatwise on one another. Moreover, it is customaryin printing devices of this general class to dispose'a suitable guard, commonly in the form of a metal loop, above the delivery table to prevent air currents from raising the freshly ejected sheet'and to guide the sheet towards its intended position over those which have previously been ejected. 'lVhenever a static charge is produced on a sheet during the imprinting of the same, this charge may cause the ejected sheet to adhere to the guard, thereby preventing the sheet from dropping by gravity upon the previously ejected sheets and also, in many cases, causing the edge of the sheet which adheres to the guard to engage and crumple the successively ejected sheets.

Attempts have heretofore been made to overcome these difficulties by causingeach imprinted sheet to pass over, or under, a conductor grounded to the metal parts of the printing device so as to dissipate the accumulated static charge by contact with the grounded conductor. This has been done, for example, by stretching a tinsel cord so close to the path of the ejected sheet as to have the strands of the tinsel engaged by the sheet during its ejecting movement. In practice, the friction between the sheets and the tinsel causes rapid wear on the latter, thereby introducing a considerable item of n'iaintenance expense. l urthermore, the tinsel soon sags and becomes inoperative if stretched below the path of the sheet and this dillicu'lty cannot be overcome by disposing the tinsel above the sheet, since it would then smearthe fresh imprinting and spoil the'looks of the sheet.

My present invention aimsto overcome all of the diliiculties heretofore encountered with such printing devices on account of the static charges on the sheets without employing any parts which are subject to an appreciable amount of wear or which are likely to become inoperative. Furthermore, my invention aims to provide a charge-dissipating device for this purpose which will not produce any friction whatever on the sheet during the ejecting movement of the latter, which will positively detach the sheet from the guard if the static charge is causing the sheet to adhere to the guard, which will assist in the downwardmovcment of the imprinted sheets towards the stack of previously printed ones, after the freshly imprinted sheet has been ejected to its full extent, and which will eject improperly timed sheets beyond the delivery table. I urthermore, my invention aims to provide a charge-dissipating device of exceedingly low cost and simple construction and one which can readily be attached to standard types of printing devices, and aims to provide simple means for operating the charge-dissipator in properly timed relation to the ejecting of the imprinted sheets. Still further and also more detailed objects will appear from the following specification and from the accompanying drawings, in which-- Fig. 1 is an end elevation of a printing device of the general class of-the multigraphs, showing an Qn'llJOClllllQnl' of my invention as attached to the same.

1* ig. 2 is a perspective view of the parts of Fig. i which comprises the delivery table, the guards for limiting the nmvenrent of the imprinted sheets-in various directions, and the charge-dis'sipator.

Fig. 3 shows parts of a modification having a clamp for facilitating the attaching of my eliminator to the machine and the detaching of the same.

7 Referring to the illustrations, Fig. 1 shows a printing device in which the frame 1 has journaled in it a shaft 2 carrying the imprinting cylinder, and in which the imprinted sheets areejected towards the right .of' that figure at some'distance above a delivery table 3. To limit the movement of the ejected sheets both outward of the delivery table and laterally of the latter, this table is provided with the usual side guards 4 and with an end guard 5. The table also has anupper-guard overhanging it, this being in the form of a wire loop 6 pivoted to the guide rod 8 of the machine below which rod the imprinted sheets are ejected.

To dissipate the charge successively from eachej'ected sheet, I providea charge dissipator which, in theembodiment of Figs. 1 andQ, includes a. bell-crank lever having a horizontal medial portion 7 pivoted to the bottom of the delivery table adjacent to the outer edge of the latter by a-pair of bearings 8. This charge-dissipating member also has an upper arm 9v which overhangs the delivery table and which is connected to one end of the medial or shaft portion 7 of the charge dissipating member, while another arm extends downwardly from the other end of the medial shaft portion 7. This downwardly directed arm 10 is con nected by a link 11 to a part of therprinting device which moves in timed relation tothe imprinting of the consecutive sheets and hence also to the ejecting of these sheets. In practice, such machines are commonly provided with a shaft 12 projecting at one-end beyond the frame of the ma chine, this shaft being connected to the drive shaft of the machine so as to rotate once during each imprintin thereby adapting it for affording a suitably timed connection to an automatic paper feeding attachment. Hence Ican readily secure the by correspondingly rocking the overhanging or discharge arm 9, so that these parts will reciprocate between the extreme positions shown respectively in full lines and in dotted lines in Fig. 1. lVhile the overhang ing arm 9 may be varied considerably in shapeand in its spacing from the top of the delivery table, I desirably form it so that in its lowermost position it will have its free end disposed below the pivoted guard 6 but somewhat above the top of the delivery table, and so that thisfree end of the arm 9 will be elevatedto a'considerable extent when the arm is in its raised position. By adjusting the position of the crank so that the arm 9 will be in this raised position when the sheet is being ejected during the normal operation of the machine, I keep this arm entirely out of the path of the sheet during the ejecting movement of the latter. Consequently, the freshly imprinted sheet when ejected (as shown at 1a in Fig. 1) will follow its usual course under the guard 6 without encountering any friction whatever on the part of my charge-dissipating arrangement.

If the weather conditions are such that no static effect has been produced on the sheet, each sheet will then fall into its delivered position in the usual manner, so that my device does not interfere in any way with the ordinary operation of the printing device. l-lowever, if a static charge has been produced on the imprinted sheet, thereby causing it to adhere more or less to the guard 6, the subsequent downward swingving of the arm 9 will pry the sheet off the guard and will also dissipate the charge from the sheet, since this arm is grounded through the metal link 11 to the metal parts of the printing device. Furthermore, the continued downward movement of the tip of the arm 9 past the guard 6 insures a prolonged enga 'cment of the sheet with this arm, so as to secure a full dissipation of the charge, and also pushes the sheet downward so as to assist a speedy and entirely flat stacking of the imprinted sheets. Consequently, I can readily secure the objects of my invention withv a device of exceedingly simple construction and low cost and'without interfering in any way with the normal operation of a printing device in all kinds of weather. Indeed, it will readily be seen that by detaching the bearings 8 from the delivery table and disconnecting the link 11 from the crank 18, my appliance can readily be detached from the printing device entirelyduring the spring and summer months.

Moreover, by disposing the sheet engaging arm 9 so that its free end in the lowei most position of that arm is below the path of the ejected sheet, I cause this arm to dispose of improperly timed sheets so as to prevent the latter from interfering with the proper stacking of subsequently ejected sheets. That is to say, if two sheets are in advertently fed at once into the machine, the imprinting is apt to cause one to slip on the other, so that the extra sheet will then be ejected in the position shown at 14 in 1 while the charge-dissipating arm 9 is in its depressed position, thus bringing this improperly timed sheet above the free end portion of the arm 9. lVhenever this occurs, the subsequent upward movement of the arm 9 will cause the latter to flip such a sheet upwardly between the shanks of the giard loop 6 and to eject the sheet beyond the delivery table. Consequently, my device also serves the important purpose of automatically disposing of the improperly timed (and hence inadequately imprinted) sheets, soas to prevent subsequently ejected sheets from catching on them and so as to obviate the necessity of any attention on the part of the operator of the machine.

However, while I have illustrated and described my invention in an embodiment including various highly desirable features of construction and arrangement, I do not wish to be limited as to these, since many changes might obviously be madewithout departing either from the spirit of my invention or from the appended claims. For example, the main rocking member of my device 'might be pivoted on a single support 15 as shown in Fig. 3 and this might be secured to the delivery table by a manually detachable clamp 16 to expedite the attaching and detaching of my device.

I claim as my invention:

1. The combination with a printing device having means for successively ejecting the printed sheets over a delivery table, of

a guard above the delivery table in the path of the ejected sheet for limiting the height of the ejected sheet above said table, a grounded member movably mounted with respect to the delivery table and disposed in proximity to the guard, and means for mov ing the grounded member in timed relation to the ejecting means to depress each sheet away from the guard after the sheet has been ejected under the guard.

2. In, a printing device having a delivery I table overhung by a pair of spaced guard members and having means for successively ejecting the printed sheets over the table below the guard members, a grounded member movably mounted with respect to the said table and having a portion thereof disposed for upward and downward movement between the guard members, and means for moving the grounded member in timed relation to the ejecting means so as to cause the said portion to move downwardly between the guard members after each sheet has been'ejected below the latter.

In a printing device having mechanism for ejecting each printed sheet above a delivery table and having a continuously ro tating crank for actuating the said sheet ejectingmechanism, a grounded member pivotally mounted and having a portion thereof overhanging the said table and movable toward and away from the table, and a connection between the crank and the grounded member for moving the latter in timed relation to the actuation of the ejecting mechanism.

4. A mechanism as per claim 3, in which the grounded member comprises a bell-crank lever having one arm thereof forming the said member portion, and in which the said connection comprises a link interposed between the crank and the other arm of the bell-crank lever.

5. The combination with a printing device having means for successively ejectin the printed sheets over a delivery table, or a guard above the delivery table in the path of the ejected sheet for limiting the height of the ejected sheet above said table, a grounded member movably mounted with iespect to the delivery table and disposed in proximity to the guard, and means for moving the grounded member in timed relation to the ejecting means to depress each sheet away from the guard after the sheet has been ejected under guard: the grounded member when in its depressed position having a portion disposed below the initial path of the ejected sheets so as to underhang a sheet ejected when the grounded member is in this position, thereby causing the sub sequent raising of the grounded member to carry such a sheet out of the path of the subsequently ejected sheets.

6. In a printing device having a delivery table overhung by a pair of spaced guard members and having means for successively ejecting the printed sheets over the table below the guard members, a grounded member m vably mounted with respect to the said table and having a portion thereof dis posed for movement from a raised position entirely above the guard members to a depressed position disposed below he guard members and means for moving the grounded member in timed relation to the ejecting means so as to dispose the said portion in its raised position during the properly timed ejection of each sheet and so as to carry the said portion downwardly to its depressed position after such ejection of the sheet; the grounded member when in its said depressed position being also below the path of the ejected sheets, so as to underhang any sheet ejected in improved timing when the said member is depressed and so as to cause the subsequent raising of the grounded member to flip such improperly ejected sheet upwardly between the guard members and out wardly over the delivery table Signed at Chicago, Illinois, November 17, 1924.

GEORGE H. MAHONEY. 

